Thumbnail, Title, Tags are the most common things that attract viewers.
Besides that annotations are the perfect method for interacting with your audience trough your video by making a small Leave a Comment or Drop a Like pop during the video.
What I like to do as far as getting views is using social media such as twitter, facebook or some other social media that you prefer. Yesterday I created a new YT channel (this one), starting out with 0 Subscribers, it's always tough. As soon as I got into twitter and spreading the word about my channel, I managed to reach 11 subscribers and people saying they'll bomb my channel with likes, haha. That's my preference.